CVE-2026-81802 in WpEvently Plugin
Summary
by MITRE • 09/08/2026
Unauthenticated Insecure Direct Object References (IDOR) in WpEvently <= 5.6.0 versions.
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Analysis
by VulDB Data Team • 09/08/2026
The vulnerability identified as an Unauthenticated Insecure Direct Object Reference within the WpEvently plugin for WordPress, affecting versions up to and including 5.6.0, represents a critical failure in access control mechanisms that allows attackers to manipulate object identifiers directly without proper authorization checks. This flaw is rooted in the application's handling of user-supplied input used as pointers to specific resources or data structures stored on the server side. In typical web applications, when a request is made for an event detail, ticket information, or administrative setting, the system should verify that the requesting user has the appropriate permissions to access that specific resource based on their role and session state. However, in this instance, the plugin fails to enforce these checks before processing requests that target internal object IDs, such as post IDs, meta data keys, or configuration parameters associated with event listings.
From a technical perspective, this vulnerability aligns closely with CWE-639, which describes Insecure Direct Object References where an application exposes a reference to an internal implementation object, such as a file, directory, or database key, and relies on the client-side input to determine which object to access. Because the validation logic is absent or insufficiently robust, an unauthenticated attacker can craft HTTP requests with manipulated parameters to enumerate valid event IDs, extract sensitive metadata associated with those events, or potentially modify administrative settings if the underlying code path allows write operations without authentication. The lack of server-side authorization checks means that any public user on the internet can interact with these endpoints as if they were an authenticated administrator or a legitimate attendee with specific privileges, depending on what data is exposed through the vulnerable parameter.
The operational impact of this vulnerability is severe due to its unauthenticated nature and potential for automated exploitation at scale. Attackers can use simple scripts to iterate through sequential event IDs, leading to mass enumeration of all events hosted on the affected WordPress site. This results in a complete loss of confidentiality regarding private or restricted event details that were intended only for registered users or specific audiences. Furthermore, if the vulnerable endpoint allows modification rather than just retrieval, it could lead to integrity violations where attackers alter event dates, locations, ticket prices, or registration limits without any oversight. In worst-case scenarios involving poorly coded meta handling, this IDOR flaw might serve as a vector for further attacks such as Local File Inclusion or SQL Injection if the input is not sanitized before being passed into database queries, although the primary classification remains an access control failure.
This vulnerability maps directly to MITRE ATT&CK technique T1078, specifically Valid Accounts and Default Accounts contexts where attackers leverage weak authentication controls, but in this case, it extends to Unauthenticated Access which falls under broader reconnaissance or initial exploitation phases depending on whether data is merely read or actively modified. It also relates to CWE-284 Improper Access Control, highlighting the fundamental design error of trusting client-side inputs for security decisions. The absence of authentication requirements makes this particularly dangerous as it does not require credential theft or session hijacking; any internet user with basic networking knowledge can exploit it using standard tools like curl or Burp Suite by simply changing an ID parameter in a URL and observing the server's response to confirm data exposure.
Mitigation strategies must focus on immediate remediation of the codebase followed by long-term security hardening practices. The most effective solution is for plugin developers to release version 5.6.1 or later, which implements strict authorization checks ensuring that every request involving object references verifies the user's current session and role permissions against a whitelist of allowed actions before returning data. For site administrators unable to update immediately due to compatibility concerns with other plugins, temporary mitigations include restricting access to specific endpoints via web application firewall rules if identifiable by unique URL patterns or parameter names associated with WpEvently functions. Additionally, implementing rate limiting on these endpoints can reduce the effectiveness of automated enumeration attacks while a permanent fix is deployed. Regular security audits and code reviews focusing on input validation and authorization logic are essential to prevent similar flaws in future updates, ensuring that all direct object references are validated against user privileges before processing.